Yuki Nitta was born in Buzen, Fukuoka Prefecture, Japan, on 10 August 1911. At some point, she moved to the Kantō region. She independently learned English and nursing, and she served as a nurse at St. Luke’s International Hospital in Tokyo. At the time of her retirement, she held the position of Chief Nurse in the Department of Obstetrics and Gynecology.

Nitta never married nor had children. After retiring, she lived with her older sister in Kamakura until she reached the age of around 90. She then returned to her hometown of Buzen. Around the age of 95, she contracted influenza, which weakened her muscles during her hospitalization. Consequently, she began receiving care services and has been residing in a nursing home ever since. According to her family, Nitta was a determined individual who maintained strict discipline in her own life and in her interactions with others.